SEL ELEKTROKIMIA : SEL VOLTA

Summary

This educational video delves into the fascinating world of electrochemistry, focusing on voltaic cells. It explains the two types of cells: voltaic cells that convert chemical energy into electrical energy and electrolytic cells that use electricity to drive chemical reactions. The video provides a detailed explanation of voltaic cells, including their working principles, electrode reactions, and the role of the salt bridge. It also covers the concept of the electrochemical series, standard reduction potentials, and how they dictate the spontaneity of redox reactions. Practical applications of voltaic cells, such as in primary and secondary batteries, are discussed, highlighting their importance in everyday life.

Takeaways

• 🔬 Electrochemistry is a branch of chemistry that studies the relationship between energy, chemistry, and electrical energy in cells.
• 🔋 There are two types of cells: the voltaic cell, which converts chemical reactions into electrical energy, and the electrolytic cell, which uses electrical energy to drive chemical reactions.
• 🔌 In a voltaic cell, two electrodes are placed in separate containers and connected by a voltmeter to measure electrical potential.
• ⚡ The electrodes are of two kinds: the cathode, which is positively charged and undergoes reduction reactions, and the anode, which is negatively charged and undergoes oxidation reactions.
• 💧 Electrodes are immersed in an electrolyte solution, which typically contains ions that match the composition of the electrodes.
• 🔄 The movement of electrons from the anode to the cathode through a wire completes the circuit and results in a flow of electric current.
• 📊 The standard reduction potential, denoted by E°, is a measure of a substance's tendency to be reduced and is used to determine the spontaneity of redox reactions.
• 🔋 The Nernst equation is used to calculate the cell potential under non-standard conditions, taking into account the concentrations of the reactants and products.
• ⚙ Applications of voltaic cells include the Leclanche cell (dry cell), the lead-acid cell (secondary cell), and fuel cells, each with specific chemical reactions and uses.
• 🌐 The script also encourages viewers to engage by asking questions in the comments, liking the video, sharing it, and subscribing for updates.

Q & A

What is electrochemistry and what are its two main branches?

Electrochemistry is a branch of chemistry that studies the relationship between energy, chemistry, and electrical energy in cells. It has two main branches: the voltaic cell, where chemical reactions in the cell can produce electrical energy, and electrolysis, where electrical energy is used to drive chemical reactions.

What are the two types of electrodes in a voltaic cell and their functions?

In a voltaic cell, there are two types of electrodes: the cathode, which is positively charged and the site of reduction reactions, and the anode, which is negatively charged and the site of oxidation reactions.

How are the electrodes connected in a voltaic cell?

The electrodes in a voltaic cell are placed in separate containers and connected by a salt bridge, which is a gel-like substance containing dissolved salt to complete the electrical circuit.

What is the role of the salt bridge in a voltaic cell?

The salt bridge in a voltaic cell serves two functions: it completes the electrical circuit of the cell and neutralizes the charge in both compartments by allowing the movement of ions.

What is the standard hydrogen electrode and how is it used?

The standard hydrogen electrode is a reference electrode used to measure the potential of other substances. It consists of a glass tube containing platinum connected to a wire, immersed in an acid solution, and bubbled with hydrogen gas at a pressure of 1 ATM.

What is the Nernst equation and how is it used in electrochemistry?

The Nernst equation is used to calculate the cell potential under non-standard conditions. It relates the cell potential to the standard reduction potential, the number of electrons transferred, and the concentrations of the reactants and products.

What is the significance of the standard reduction potential (E°) in electrochemistry?

The standard reduction potential (E°) indicates the tendency of a substance to be reduced. The more positive the value, the more readily the substance can be reduced, indicating a stronger reducing power.

How is the potential of a voltaic cell determined?

The potential of a voltaic cell is determined by the difference in reduction potentials of the anode and cathode reactions. The cell potential is calculated by subtracting the standard reduction potential of the anode reaction from that of the cathode reaction.

What are some applications of voltaic cells mentioned in the script?

Some applications of voltaic cells include the Leclanche cell used in dry batteries, the lead-acid cell used in secondary batteries, and fuel cells which are efficient and produce water as a byproduct.

How does the reaction in a fuel cell differ from other types of voltaic cells?

In a fuel cell, the reaction produces water as the only byproduct, making it an emission-free energy source. The reaction involves hydrogen and oxygen gases with a NaOH electrolyte, resulting in a clean energy conversion process.

Outlines

00:00

🔬 Introduction to Electrochemistry and Voltaic Cells

This paragraph introduces the topic of electrochemistry, a branch of chemistry that studies the relationship between energy, chemistry, and electrical energy in cells. It explains that electrochemistry has two main branches: voltaic cells, where chemical reactions produce electrical energy, and electrolysis, where electrical energy is used to drive chemical reactions. The focus of the video is on voltaic cells, starting with a diagram and the working principle of a voltaic cell. The cell consists of two electrodes placed in separate containers and connected by a voltmeter. The electrodes are where redox reactions occur, with the cathode being positively charged and the site of reduction reactions, and the anode being negatively charged and the site of oxidation reactions. Both electrodes are immersed in an electrolyte solution containing ions that match the composition of the electrodes. The containers are connected by a salt bridge, typically a gel with dissolved salt like KNO3. The paragraph discusses the redox process using copper and iron as examples, detailing how electrons flow from the anode to the cathode, leading to the reduction of ions at the cathode. The movement of electrons causes an imbalance of charge in the containers, which is balanced by the salt bridge. The paragraph concludes with a discussion of the redox reactions at the electrodes and how they can be balanced and represented in a cell notation.

05:01

🔋 Understanding Voltaic Series and Standard Reduction Potentials

This paragraph delves into the concept of the voltaic series, which is a list of elements arranged according to their standard reduction potentials. The series starts with the most easily oxidized elements on the left and progresses to the most easily reduced elements on the right. The paragraph explains that elements on the left have more negative reduction potentials, indicating a stronger reducing power, while those on the right have more positive potentials, indicating a stronger oxidizing power. The paragraph then provides an example problem to illustrate how to write the anode, cathode, and cell reactions for a given voltaic cell. It explains how to balance the electron transfer in the reactions and how to use the standard reduction potentials to calculate the cell potential. The paragraph also introduces the concept of the standard reduction potential, denoted by E°, which represents the tendency of a substance to be reduced. It explains how this potential is measured against a reference electrode, typically the hydrogen electrode, under standard conditions. The paragraph concludes with a brief discussion on how to calculate the cell potential under non-standard conditions using the Nernst equation.

10:01

🔬 Calculation of Cell Potential and Non-Standard Conditions

This paragraph discusses the calculation of cell potential in both standard and non-standard conditions. In standard conditions, the paragraph explains how to determine the cell potential by using the known standard reduction potentials of the electrodes and ensuring the electron transfer is balanced. It provides a formula for calculating the cell potential (E°cell = E°cathode - E°anode) and demonstrates it with an example. The paragraph then moves on to non-standard conditions, where the concentrations of the reactants are not 1 M. It introduces the Nernst equation for calculating the cell potential under these conditions, which takes into account the concentrations of the products and reactants. The paragraph explains the terms involved in the Nernst equation, such as the number of electrons transferred, the reaction quotient, and the concentrations of the species involved. It also provides an example problem to illustrate the application of the Nernst equation and how to calculate the cell potential for a voltaic cell with given concentrations of reactants.

15:02

🔋 Applications of Voltaic Cells

This paragraph explores the various applications of voltaic cells. It begins by describing the Leclanché cell, also known as a dry cell, which is commonly used as a battery. The paragraph details the components of the Leclanché cell, including the graphite rod cathode, zinc anode, and the electrolyte paste of MnO2. It explains the reactions occurring at the electrodes and the overall cell reaction. The paragraph then discusses the lead-acid (Pb-Acid) cell, which is a secondary cell with lead and lead dioxide as the electrodes and sulfuric acid as the electrolyte. It outlines the reactions at the electrodes and the overall cell reaction during discharge. The paragraph also mentions that the lead-acid cell has two types of reactions: charging (electrolysis) and discharging (voltaic cell reaction). Lastly, the paragraph introduces the fuel cell, highlighting its high efficiency and zero-emission characteristics. It describes the use of hydrogen and oxygen gases with a NaOH electrolyte and the reactions at the electrodes, which result in water as the only emission product. The paragraph concludes by encouraging viewers to ask questions and engage with the content through likes, shares, and subscriptions.

20:05

🌐 Conclusion and Engagement Invitation

The final paragraph serves as a conclusion to the video, summarizing the key points discussed and inviting viewer engagement. It reiterates the importance of understanding the principles and applications of voltaic cells, including their reactions and potential calculations. The paragraph encourages viewers to ask questions in the comments section if they have any doubts or need further clarification. It also prompts viewers to like the video, share it with friends, and subscribe to the channel for updates on new videos. The paragraph ends with a motivational note, thanking viewers for their attention and encouraging them to continue learning.

Keywords

💡Electrochemistry

Electrochemistry is a branch of chemistry that studies the relationship between energy, chemical reactions, and electrical energy in cells. In the video, electrochemistry is the central theme, with a focus on how chemical reactions in cells can produce electrical energy, as well as how electrical energy can drive chemical reactions.

💡Voltaic Cell

A voltaic cell, also known as a galvanic cell, is a type of electrochemical cell where a spontaneous chemical reaction generates electrical energy. The video explains the voltaic cell by discussing its components, such as electrodes and electrolytes, and how they function together to produce an electric current.

💡Electrode

An electrode is a conductor through which electricity enters or leaves a device, such as a battery or a cell. In the context of the video, electrodes are the sites where redox reactions occur. They are of two types: the anode, which is negatively charged and undergoes oxidation, and the cathode, which is positively charged and undergoes reduction.

💡Redox Reactions

Redox reactions are chemical reactions that involve the transfer of electrons between atoms. The term 'redox' is a shorthand for reduction-oxidation. In the video, redox reactions are central to the operation of voltaic cells, where electrons are transferred from the anode to the cathode, generating an electric current.

💡Electrolyte

An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water. In the video, the electrolyte is the medium that contains ions of the same type as the electrodes and allows for the flow of ions between the anode and cathode, thus facilitating the redox reactions.

💡Oxidation

Oxidation is a chemical process that involves the loss of electrons or an increase in the oxidation state of an atom. In the video, oxidation occurs at the anode, where a metal, such as zinc, loses electrons and becomes ions that enter the electrolyte.

💡Reduction

Reduction is a chemical process that involves the gain of electrons or a decrease in the oxidation state of an atom. In the video, reduction takes place at the cathode, where ions in the electrolyte gain electrons and are deposited on the electrode.

💡Standard Reduction Potential

Standard reduction potential, symbolized as E°, is a measure of the tendency of a substance to be reduced. It is a key concept in the video as it helps to determine the feasibility of redox reactions in a voltaic cell. The higher the potential, the more likely the substance is to be reduced.

💡Nernst Equation

The Nernst equation is used to calculate the cell potential under non-standard conditions, taking into account the concentrations of the reactants and products. In the video, the Nernst equation is introduced to explain how the cell potential changes with varying concentrations of electrolytes, which is crucial for understanding the performance of voltaic cells under different conditions.

💡Fuel Cell

A fuel cell is a type of electrochemical cell that converts the chemical energy from a fuel into electricity through a redox reaction. In the video, fuel cells are mentioned as an application of voltaic cells, where hydrogen and oxygen react to produce water and electricity, highlighting their efficiency and environmental benefits.

Highlights

Electrochemistry is a branch of chemistry that studies the relationship between energy, chemistry, and electrical energy in cells.

There are two types of cells in electrochemistry: the voltaic cell, which generates electrical energy from chemical reactions, and the electrolytic cell, which uses electricity to drive chemical reactions.

A voltaic cell consists of two electrodes placed in separate containers and connected by a voltmeter to read the electrical voltage.

Electrodes are of two types: the cathode, which is positively charged and site of reduction reactions, and the anode, which is negatively charged and site of oxidation reactions.

The electrodes are immersed in an electrolyte solution containing ions that match the composition of the electrodes.

The function of the salt bridge is to complete the electrical circuit of the cell and neutralize charges in both compartments.

The oxidation reaction at the anode involves the loss of electrons, while the reduction reaction at the cathode involves the gain of electrons.

The movement of electrons from the anode to the cathode results in an imbalance of charge in both compartments, which is neutralized by the salt bridge.

The reactions at the electrodes can be balanced by adjusting the number of electrons involved, resulting in the overall cell reaction.

The standard reduction potential, denoted by E°, indicates the tendency of a substance to be reduced and is measured against a standard hydrogen electrode.

The Nernst equation is used to calculate the cell potential under non-standard conditions, taking into account the concentrations of the reactants and products.

The standard hydrogen electrode is used as a reference with a potential of 0 volts, and the potential of other electrodes is measured relative to it.

The voltage of a cell can be calculated using the standard reduction potentials of the half-reactions and the number of electrons transferred.

The concept of the electrochemical series is introduced, which ranks elements by their tendency to undergo oxidation or reduction.

The Leclanché cell, a common dry cell battery, is an example of a voltaic cell with a zinc anode and a manganese dioxide cathode.

The lead-acid battery is a secondary cell where the lead anode undergoes oxidation and the lead dioxide cathode undergoes reduction.

Fuel cells are an attractive type of cell due to their high efficiency and clean emissions, producing only water as a byproduct.

The reactions in a fuel cell involve the oxidation of hydrogen at the anode and the reduction of oxygen at the cathode, with the overall reaction producing water.

Transcripts

Hai Hai guys di video kali ini kita akan

belajar mengenai sel elektrokimia

elektrokimia merupakan cabang ilmu kimia

yang mempelajari hubungan antara energi

kimia dan energi listrik sel

elektrokimia sendiri ada dua guys yaitu

sel volta dimana reaksi kimia pada sel

dapat menghasilkan energi listrik dan

kedua sel elektrolisis dimana energi

listrik digunakan untuk menjalankan

reaksi kimia di video ini kita akan

lebih fokus membahas sel volta dimulai

dengan bagan dan prinsip kerja sel volta

bagan sel volta seperti berikut kedua

elektroda berada pada wadah terpisah dan

dihubungkan dengan suatu voltmeter

sebagai pembaca tegangan listrik

elektroda

merupakan tempat terjadinya reaksi

redoks guys dan elektroda ada dua jenis

yaitu katoda yang bermuatan positif

sebagai tempat terjadinya reaksi reduksi

dan anoda yang bermuatan negatif sebagai

tempat terjadinya reaksi oksidasi kedua

elektroda dicelupkan ke dalam suatu

larutan elektrolit yang biasanya

mengandung ion yang sama dengan penyusun

elektrodanya kedua wadah elektroda

dihubungkan oleh suatu jembatan garam

yang didalamnya berupa padatan seperti

agar-agar dengan garam terlarut

contohnya kno3 Oke Guys berikutnya Mari

kita lihat proses reaksi redoks nya ya

kita misalkan dulu katodanya adalah

logam tembaga dan anodanya Logam besi

katoda dicelupkan kedalam larutan CuSO4

sehingga di dalam larutan terdapat

ion-ion CO2 positif dan so42

Steve anoda dicelupkan kedalam larutan

feso4 sehingga didalamnya terdapat

ion-ion V2 positif dan so42 negatif

dianoda elektroda FTV akan teroksidasi

membentuk ion V2 positif dan melepaskan

elektron elektron yang dilepas lalu

mengalir melalui kawat menuju ke katoda

yang kemudian akan ditangkap oleh ion

CO2 positif yang ada di dalam larutan

hal ini mengakibatkan ion CO2 positif

akan tereduksi dan terdeposit atau

mengendap di katoda

Hai akibat pergerakan elektron dari

anoda menuju ke katoda menyebabkan

muatan di kedua wadah menjadi tidak

seimbang dan disinilah peran dari

jembatan garam guys bila kita perhatikan

di anoda terdapat kelebihan ion positif

akibat oksidasi elektroda V sehingga

kelebihan muatan positif itu akan

dinetralkan oleh ion negatif dari

jembatan garam sedangkan di katoda

karena kekurangan muatan positif akibat

reduksi ion CO2 positif maka ion positif

dari jembatan garam akan menetralkan ion

negatif dalam larutan jadi jembatan

garam memiliki dua fungsi guys yaitu

menghantarkan arus listrik dengan

menutup rangkaian sel dalam

Hai dan menetralkan muatan di kedua

wadah

Hai reaksi di anoda merupakan reaksi

oksidasi Fe menjadi fe2 positif tambah

dua elektron dan reaksi di katoda

merupakan reduksi ion CO2 positif Plus 2

elektron menjadi CEO elektron di kedua

reaksi sudah setara sehingga bisa kita

coret jadi reaksi selnya yaitu FPI

ditambah dengan co2 positif menjadi fe2

positif ditambah dengan CEO dari reaksi

sel kita bisa membuat notasi atau

diagram selnya formatnya yaitu di

sebelah kiri anoda dan di sebelah kanan

katoda atau di sebelah kiri yang

mengalami oksidasi dan di sebelah kanan

yang mengalami reduksi dari reaksi sel

tadi kita bisa Tuliskan menjadi seperti

berikut V yang teroksidasi terletak di

sebelah kiri yaitu anoda dan

dan CO2 positif yang tereduksi terletak

di sebelah kanan yaitu katoda garis

tunggal di masing-masing elektroda

menyatakan batas fase dan garis2 di

tengah menyatakan jembatan garam

Hai berikutnya Mari kita bahas deret

volta deret volta merupakan suatu deret

unsur-unsur berdasarkan nilai potensial

reduksi standar nya atau disimbolkan

dengan enol deret volta dimulai dari

unsur Eli hingga atau dengan unsur

hidrogen atau ha menjadi batas Karena

memiliki nilai potensial reduksi sebesar

novol semakin ke kiri nilai potensial

reduksi akan semakin kecil atau bernilai

negatif sehingga unsur-unsur semakin

mudah mengalami oksidasi dengan kata

lain semakin kuat daya pereduksinya

semakin ke kanan nilai potensial reduksi

semakin besar atau bernilai positif

sehingga unsur-unsur semakin mudah

mengalami reduksi atau dengan kata lain

semakin kuat daya pengoksidasi nya

Hai agar teman-teman lebih paham Mari

kita bahas contoh soal berikut ya

tuliskan reaksi anode reaksi katode dan

reaksi sel dari sel-sel dibawah ini a

CEO teroksidasi menjadi CO2 positif dan

AG positif tereduksi menjadi agbro3 si

menjadi al3 positif dan ni2 positif

tereduksi menjadi ni oke Guys kita bahas

yang a dulu ya Sesuai dengan format

diagram atau notasi sel yang tadi telah

kita pelajari di bagian kiri merupakan

oksidasi di anoda dan dibagian kanan

merupakan reduksi dikatoda jadi reaksi

anodanya yaitu CEO menjadi CO2 positif

tambah dua elektron lalu reaksi di

katoda Age positif tambah elektron

menjadi

Ayo kita setarakan elektronnya dianoda

kita kali satu dan di katoda kita kali

dua sehingga dianoda tetap dan di katoda

reaksinya 2ag positif tambah dua

elektron menjadi 2ag elektronnya bisa

kita coret atau kita eliminasi dan kita

dapatkan reaksi selnya 2ag positif

tambah CEO menjadi 2 AG + CO2 positif

berikutnya yang B reaksi di anoda yaitu

awal menjadi al3 positif + 3 elektron

dan di katoda ni2 positif Plus 2

elektron menjadi Eni kita setarakan lagi

elektronnya Guys dianoda kita kali dua

dan di katoda kita kali tiga sehingga

reaksi di anoda 2 Al menjadi dua al3

positif tambah 6 elektron

reaksi di katoda 3eny dua positif tambah

6 elektron menjadi tiga Emi elektronnya

bisa kita eliminasi lalu kita dapatkan

reaksi selnya 3eny dua positif tambah 2

Al menjadi 3eny Plus 2 Al tiga positif

nah sampai di sini bisa dipahami aguis

jika sudah paham Mari kita lanjut ke

materi berikutnya mengenai potensial

reduksi standar potensial reduksi

standar yang disimbolkan dengan enol

merupakan nilai yang menyatakan

kecenderungan suatu zat untuk tereduksi

semakin positif Nilai N halnya maka

semakin mudah untuk mengalami reduksi

guys

Hai penentuan atau pengukuran nilai Enno

suatu zat dilakukan dengan membandingkan

potensial listrik suatu zat terhadap

suatu elektroda pembanding dalam keadaan

standart elektroda pembanding yang

biasanya digunakan adalah elektroda

hidrogen yaitu suatu tabung kaca yang

didalamnya terdapat platina yang

dihubungkan dengan kawat dicelupkan

dalam larutan asam dan dialiri gas

hidrogen kondisi standar yang dimaksud

yaitu konsentrasi larutan memiliki nilai

1 molar elektroda hidrogen menggunakan

larutan asam yang konsentrasi ha

positifnya sebesar 1 molar kondisi

berikutnya tekanan yang digunakan

sebesar 1 ATM jadi aliran gas hidrogen

dibuat pada tekanan 1 ATM guys

pengukuran juga dilakukan pada suhu 25°

celcius karena nilai potensial reduksi

hidrogen adalah

now hold maka nilai yang terbaca di

voltmeter merupakan nilai potensial

reduksi dari zat yang diukur

Hai berikutnya kita belajar perhitungan

potensial.sel perhitungan ini dibagi

dalam dua keadaan guys yang pertama

dalam keadaan standar kita misalkan

terdapat 2 elektroda yang masing-masing

diketahui nilai potensial reduksinya

ingat kembali ya guys nilai yang lebih

positif yang lebih mudah mengalami

reduksi jadi yang tereduksi yaitu Age

sementara ZN mengalami oksidasi sehingga

reaksinya harus kita balik dan nilai

email-nya berubah tanda menjadi positif

lalu kita setarakan elektronnya sehingga

elektronnya bisa kita eliminasi dan kita

dapatkan nilai potensial sel untuk

reaksi ZN + 2 AG positif menjadi zm2

positif + 2 AG sebesar positif 1,56 volt

bisa juga kita hitung dengan menggunakan

rumus if

nosel = Enno reduksi dikurang n oksidasi

atau fenol katoda kurang Enno anoda jadi

dengan rumus ini maka 0,8 kurang minus

0,76 = positif 1,56 volt nilai positif

artinya reaksi berlangsung spontan atau

dapat terjadi keadaan kedua yaitu tidak

standar konsentrasinya bukan 1 molar

nilai potensial sel kita hitung dengan

menggunakan persamaan nernst dimana SL

sama dengan enol sel kurang 0,05 92

keren kali loh

Hai handphone merupakan jumlah elektron

yang terlibat atau yang sudah

disetarakan sementara QC merupakan

question reaksi dengan rumus konsentrasi

produk ^ koefisien bagi konsentrasi

reaktan ^ koefisien ingat ya guys

produknya adalah ion yang terbentuk di

anoda sedangkan reaktan merupakan ion

yang ada di katoda jadi bisa kita

Tuliskan konsentrasi anoda ^ koefisien

bagi konsentrasi katoda ^ koefisien dan

jika dalam fase gas konsentrasi bisa

digantikan dengan tekanan Nah agar

teman-teman lebih paham penggunaan

rumusnya Mari kita bahas contoh soalnya

Ya diketahui harga potensial standar sel

sebagai berikut pertanyaannya yang a7la

a b c dan

di berdasarkan daya pereduksi dimulai

dari pereduksi paling kuat yang B

tentukan potensial standar atau anosel

dari notasi berikut Oke Guys kita mulai

dari pertanyaan yang aduh untuk

menentukan susunan a b c dan d kita bisa

menggunakan konsep deret volta bagian

kiri De volta yang mengalami oksidasi

bagian kanan yang mengalami reduksi

langkah pertama kita tentukan dulu

posisi zat yang reaksi selnya memiliki

potensial paling besar berarti lokasi

Sheila dan C nilai potensial selnya

positif guys berarti reaksi redoks nya

dapat berlangsung ya atau spontan zat

a-bank alami oksidasi berarti di sebelah

kiri pada deret volta ya guys dan zat C

mengalami reduksi berarti di sebelah

kanan deret volta nilai potensial nya

sebesar 3,55 vol

Hai berikutnya C dengan b nilai

potensial selnya negatif berarti tidak

dapat berlangsung atau tidak spontan

supaya reaksinya bisa berlangsung maka

harus kita balik guys sehingga B yang

mengalami oksidasi dan C yang mengalami

reduksi jadi B sekarang ada di sebelah

kiri dan C berada di sebelah kanan

dengan beda potensial sebesar 0,98 volt

terakhir antara a dengan C bernilai

positif juga berarti bisa berlangsung

atau spontan sehingga A ada di sebelah

kiri dan D ada di sebelah kanan dengan

beda potensial sebesar 2,4 7fold posisi

D tidak diantara b&c ya karena nilai 2,4

7fold ini tidak melebihi selisih AC

kurang

Hai maka berdasarkan susunan yang sudah

kita buat susunan daya pereduksi dari

yang paling kuat berarti dimulai dari

paling kiri guys yaitu adab2 luce

selanjutnya kita mencari nilai potensial

sel dari notasi sel DB kita dapatkan

dari nilai potensial AC dikurang b c

dikurang ad Jadi 3,55 kurang 0,98

dikurang 2,4 7 kita dapatkan hasilnya

sebesar positif 0,1 Fold

Hai nah sampai di sini bisa dipahami ya

guys Mari kita bahas contoh soal yang

berikutnya tentukan potensial sel volta

berikut ZN + CO2 positif 2 molar menjadi

zm20 sitif 1 molar tambah CPU yang B2

Agi positif 1 molar tambah EMG menjadi 2

AG + mg2 positif 0,01 molar

hai oke Guys kita selesaikan dengan

menggunakan rumus persamaan dan studi ya

untuk yang atau lebih dahulu setengah

reaksi oksidasi dan reduksi adalah

sebagai berikut dan nilai potensial

reduksinya kita ambil dari buku atau

dari sumber lain ya guys rumus ini kita

bisa Uraikan lagi menjadi Enno reduksi

kurang n oksidasi kurang 0,05 92 permen

kali lock konsentrasi zm20 sitif bagi

konsentrasi CO2 positif masing-masing

berpangkat satu karena koefisiennya

masing-masing juga satu ya guys sama

dengan 0,34 kurang minus 0,76 kurang

0,05 90/2 ya elektron yang sudah setara

dikali log 1/2 hasil perhitungannya kita

dapatkan sebesar positif 1 koma 11 vol

Hai selanjutnya yang B dengan rumus yang

sama persamaan setengah reaksinya adalah

sebagai berikut dan bila kita Uraikan

rumusnya menjadi Enno reduksi kurang

Enno oksidasi kurang 0,05 92 per n kali

lock konsentrasi mg2 positif pangkat-1

berkonsentrasi LG positif ^ 2 = 0,8

kurang minus 2,37 kurang 0,05 9202 kali

lock 0,01 persatu kuadrat kita dapatkan

hasilnya sebesar positif 3,2 3-fold

buckle

Hai nah sampai di sini bisa dipahami ya

guys

Hai jika sudah paham Mari kita lanjut ke

materi berikutnya mengenai aplikasi sel

volta berikut adalah beberapa aplikasi

dari sel volta guys yang pertama sel

leclanche atau sel kering atau disebut

juga sel primer biasanya sel kering ini

dimanfaatkan sebagai baterai nah

contohnya pada gambar berikut kita lihat

bahwa katodanya merupakan batang grafit

dan anodanya dibuat dari unsur zinc

elektrolitnya yaitu pasta mno2 jadi

reaksi yang ada di masing-masing

elektroda yaitu dianoda ZN menjadi zm2

positif tambah dua elektron dan di

katoda dua mno2 + 2 nh4 positif Plus 2

elektron menjadi mn2o 3 plus 2 NH3 + H2O

sehingga reaksi selnya

Hai yaitu ZN + 2 mno2 + 2 nh4 positif

menjadi mn2o 3 plus 2 NH3 + H2O + ZN dua

positif

Hai berikutnya sel aki atau sel sekunder

fun nodanya dibuat dari PB dan katodanya

merupakan pbo2 larutan elektrolit yang

digunakan adalah larutan H2 so4 guys

Reaksi yang terjadi di anoda yaitu PB

tambah so42 negatif menjadi pbso4 Plus 2

elektron di katoda pbo2 tambah s42

negatif + 4 H plus plus 2 elektron

menjadi pbso4 + 2 H2O sehingga reaksi

selnya menjadi PB tambah pbo2 + 2 H2 so4

menjadi dua pbso4 + 2 H2O nah reaksi ini

merupakan reaksi pada saat sel aki

digunakan sebagai sumber arus guys

karena kita tahu bahwa aki punya dua

jenis reaksi

Hai yaitu reaksi pengisian ya reaksi

pengisian arus yang merupakan jenis

reaksi elektrolisis dan reaksi

pengosongan yang digunakan sebagai

sumber arus merupakan reaksi sel volta

berikutnya sel bahan bakar atau file

Hai nah sel bahan bakar ini merupakan

sel yang cukup menarik guys karena

sangat banyak aplikasinya efisiensinya

sangat tinggi dan penggunaannya sangat

bebas emisi karena hasil reaksinya hanya

menghasilkan air jadi kalau kita lihat

pada gambarnya digunakan gas hidrogen

dan gas oksigen dengan elektrolit NaOH

jadi nanti reaksi di anoda yaitu h-2 +

dua oh Amin menjadi 2 H2O + 2 elektron

sementara reaksi di katoda yaitu O2 + 2

H2O + 4 elektron menjadi empat oh Amin

dan setelah elektromedis Tarakan kita

dapatkan reaksi selnya yaitu 2 H2 + O2

menjadi 2 H2O Jadi terlihat ya hasil

dari emisi sel bahan bakar ini hanya

berupa air

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paham atau mungkin memiliki pertanyaan

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